This application claims the priority of German application 100 51 669.6, filed Oct. 18, 2000, the disclosure of which is expressly incorporated by reference herein.
The present invention relates to a device for guiding a seat of a vehicle, in particular a motor vehicle, having a running-rail arrangement comprising at least one guide rail arranged on the seat and at least one sliding rail fastened to the vehicle, and having a deformation element which absorbs energy in the event of a crash.
In conventional vehicles, the front seats, in particular, are arranged such that they can be moved, with the result that an optimum seat position can be set as a function of the size of a particular vehicle occupant. For this purpose, the seat is usually arranged in a manner such that it can be moved in the vehicle by means of a running-rail arrangement. The occupant can therefore bring the seat of the vehicle into a desired position by means of an adjusting lever, for example.
In the event of a collision, forces of inertia, which may be considerable, depending on the severity of the collision, act on the occupant. These forces are transmitted by the occupant, who is pressed into a backrest of the seat of the vehicle, to the known device for guiding the seat. In this case, the running-rail arrangement of the known device, with which arrangement the seat of the vehicle is fastened moveably to the vehicle floor, is, in particular, subjected to a considerable mechanical stress.
In order to reduce at least some of the force or energy acting on the vehicle occupant, in a device known from practice, deformation elements are provided for guiding the seat, with the result that these deformation elements can absorb the energy which occurs, reducing the energy acting on the occupant as a result.
A device of this type for guiding the seat of the vehicle is also disclosed in German patent publication DE 196 13 506 C2. This known device consists of the running-rail arrangement which is designed as a pair of seat rails. The known running-rail arrangement has at least one sliding rail designed as the lower rail and at least one guide rail designed as the upper rail. The lower rail is connected to the vehicle floor. The upper rail is guided in a manner such that it can be displaced longitudinally in the lower rail and is connected to the seat of the vehicle. Rolling elements or sliding elements, for example, which enable the seat of the vehicle to be displaced in a low-friction manner may be provided between the lower rail and the upper rail.
Furthermore, a slide fastened to the lower rail is provided. The seat of the vehicle is arranged in a manner such that it can be moved together with the upper rail in the lower rail in such a way that the seat can be arrested in a desired position on the slide or on the lower rail by means of an arresting element designed as a locking device. For this purpose, the locking device has latching elements arranged on the upper rail and on the slide. The slide is fastened to the lower rail via a predetermined breaking point. In the event of a collision, this predetermined breaking point is then intended to break, so that the slide can be moved together with the seat of the vehicle relative to the lower rail.
In addition, at least one deformation element designed as an energy-absorbing element is provided on the slide. The deformation element has webs, for example, in which a wedge-shaped element arranged on the lower rail can engage in the event of a collision. The webs are deformed, with energy being absorbed, in the event of a collision by the wedge-shaped element until the webs are destroyed.
This known device has the disadvantage that, after a collision, both the sliding rail, which is designed as the lower rail, and the slide have to be replaced. The reason for this is that, firstly, the slide equipped with the deformation element and, secondly, the lower rail having the wedge-shaped element, for example, are deformed considerably or destroyed. Moreover, in the known device, the deformation elements absorb energy merely in one direction. As a result, relief of the load on the vehicle occupant is possible only in the event of a rear-end collision or only in the event of a front-end collision.
Furthermore, the structural outlay in the known device is considerable, since, in addition to the guide rail and the sliding rail and the arresting element formed as a latching element, the running-rail arrangement also has a slide.
German patent publication DE 39 06 659 C2 discloses a seat guide for a vehicle seat, in which a deformation element for reducing energy is arranged on a sliding rail and on a driving device and a rack. However, in this known solution, the energy absorption in the event of a crash is likewise achieved by a complex and costly mechanism.
One object of the invention is to provide a device for guiding a seat of a vehicle which is further improved with regard to vehicle occupant safety and fitting outlay, in particular after a collision.
According to the invention, this object is achieved by a device for guiding a seat of a vehicle including a running-rail arrangement having at least one guide rail arranged on the seat and at least one sliding rail fastened to the vehicle. At least one arresting element arrests the seat in a desired position on the sliding rail and has at least one deformation element which absorbs energy in the event of a crash.
The device according to the invention affords the advantage that only the deformation element is deformed in a collision. Further components of the running-rail arrangement are not deformed or destroyed in the event of a collision. Therefore, after the vehicle has been involved in an accident, only the deformation element of the device according to the invention has to be exchanged.
Furthermore, the energy acting on the occupant and on the device in a rear-end impact and in a frontal impact of the vehicle can be absorbed by the device according to the invention. This is achieved in particular in that the deformation element can be displaced in both directions and hence a reduction in energy can be achieved in every event of a collision.
Furthermore, it is advantageous in the device according to the invention that an arresting element of the running-rail arrangement is coupled to the sliding rail via the deformation element. An additional slide is therefore not required. As a result, the fitting or structural outlay in the device according to the invention is minimized.
An advantageous development of the invention makes provision for the deformation element to be able to be displaced in a recess on the guide rail. Since the recess is of tapered design in the direction of displacement of the deformation element, in the event of a collision, energy can be absorbed since the deformation element is deformed in the tapering recess and the friction between the deformation element and the guide rail is increased during the displacement.
It is conceivable for the recess to be designed, for example, essentially in the shape of an elongated hole or the like. A deformation element, which is formed in the shape of a plate or the like, can then be displaced in the recess by guide elements, in the form of a bolt, for example, in the recess. Of course, other structural designs of the guide elements are also possible.
Furthermore, it is possible for the deformation element to have an energy-absorbing deformation section. It is advantageous if two deformation elements, each having a deformation section, are provided. For example, the deformation elements can then be arranged in such a manner that when the deformation element is moved both in one direction of displacement and in the other direction of displacement, a corresponding deformation of the deformation element is ensured. The deformation element can therefore absorb energy both in a rear-end collision and in a frontal collision of the motor vehicle.
It is particularly advantageous if the deformation element is provided as bent sheet metal, in which case the deformation section is then bent in a wavy manner, for example. Very great energy absorption is therefore made possible. It is also possible for the deformation element, as bent sheet metal, to be configured in the form of a spring.
Alternatively, the deformation section can also be designed as a honeycomb structure or similar structure. It is also conceivable for the deformation element to be manufactured from a metallic material, particularly if the deformation section is of wavy design. If the deformation element is to have a honeycomb structure, it is also possible that, in addition, a material manufactured from plastic can be used as filling for the honeycomb structure.
Of course, the deformation element can also be produced entirely from a material which absorbs energy, such as metal, plastic or similar material.
Irrespective of the particular design of the deformation element, there is also the advantage that the displaceability or the path of displacement of the seat of the vehicle in a collision can be limited by the length of the recess.
Further advantages and advantageous refinements of the invention become clear from the patent claims and from the exemplary embodiments described below in principle with reference to the drawings: